Horse racing is one of the oldest sports in history. Its basic concept has undergone little change over the centuries, but it has grown from a primitive contest of speed or stamina between two horses to a worldwide spectacle with large fields of runners and sophisticated electronic monitoring equipment. Its betting has evolved from private bets to bookmaking, then to the pari-mutuel system in which all bettors share a common pool of money minus a fee for the track’s management.

A horse race is a sporting event in which horses are ridden by jockeys and compete to cross the finish line first. The rules of each race govern the manner in which the horses must be guided to the finish, and the prize money is distributed according to the place results. In addition to the main races, many countries have local stakes.

Horse races are a major industry, supporting jobs in the breeding, training, and riding of horses. The sport also supports a number of related businesses, including stables, racetracks, and betting shops. It is estimated that the sport provides billions of dollars in income for its participants.

The early history of horse racing is unclear, but by the reign of Louis XIV (1643-1715), it had become a popular pastime among the upper classes. It became a popular form of gambling and a significant source of revenue for the French state. Louis’s government legislated a series of regulations to control the sport. These included requiring certificates of origin for horses, imposing extra weight on foreign competitors, and limiting the number of races open to three-year-olds.

During the eighteenth century, many of the world’s most famous horse races were held in France. These were the King’s Plates, which began in 1751, the Prix de l’Arc de Triomphe, and the Grand Prix du Jockey Club. The King’s Plates were standardized races for six-year-olds who carried 168 pounds (63 kg) in four-mile heats, and a winner had to win two of the heats. Five-year-olds and four-year-olds were allowed to race with increased weight beginning in the 1730s, and heat racing for these age groups continued until the 1860s.

In the nineteenth century, several races were reorganized. For example, the King’s Plates were restructured to allow five- and four-year-olds to carry increased weight. The classic age of the horse reached its zenith in the 1850s, and today most horses are retired at the age of five years.

Modern horse races are often run over a course that includes barriers, and a number of different distances. In the United States, for example, most horse races are run over a mile and a quarter. Other lengths include seven furlongs, half miles, and ten and twenty-four furlongs. The latter are often referred to as sprint races and are run at the fastest possible speed over short distances. In some countries, a quarter-mile is a standard sprint distance. A horse can be ridden in flat or jumps races, depending on its age and ability.